Preparation of Potassium Tris(Oxalato)iron(lll)Trihydrate, K₃Fe(C₂O₄)₃•3H₂O.

FeCl₃ + 3K₂C₂O₄  + 3H₂O    --> K₃Fe(C₂O₄)₃•3H₂O + 3KCl

(a)      Place ~8.0 g of potassium oxalate, K₂C₂O₄·H₂O, into a clean 100 mL beaker. Place a boiling stick in the beaker. Dissolve the solid in about 15 mL of water by heating gently using a hot plate (do not let solution boil!). Record the mass of the potassium oxalate.

(b)      Remove the beaker from the hot plate and allow to cool sufficiently until beaker able to be held.

(c)      Measure 5 mL of 1.5 mol L^-1 iron(III) chloride solution into 25 mL measuring cylinder. Calculate the number of moles of iron(III) chloride obtained in this step.

Add into the beaker containing potassium oxalate solution while this solution is still hot and stir with boiling stick. Record any observations.

(d)      Place beaker into ice in plastic pot for at least 15 minutes and allow solution to cool to ensure complete precipitation.

(e)      Collect the solid that forms by decanting the solution and discarding the liquid.

(f)       Recrystallisation of the iron(III) complex is carried out by dissolving the solid in the beaker in 15 mL of warm water until a clear green solution forms. It may be necessary to heat the solution gently on a hot plate while stirring using a boiling stick to redissolve all of the solid. Remove the boiling stick and place beaker in a fresh ice bath. Allow the solution to stand in ice for at least 20 minutes. If no crystals start to form within 10 minutes, advise your supervisor.

(g)      Collect the solid by vacuum filtration using a Büchner funnel and flask as shown in the diagram above. Rinse the solid in the Buchner funnel with 5mL acetone and continue to suck air through crystals until dry. Dispose of the filtrate into the waste bottle in the fume hood.

(h)      Transfer the dry crystals to a clean, dry glass vial. 2.0960 g was formed.

1: Refer to the information on the preparation of potassium tris(oxalate)iron(III) trihydrate. Has a reaction occurred? Explain your reasoning based on your observation.